Strengthening structures with externally prestressed tendons: literature review
2005 (English)Report (Other academic)
Strengthening and/or upgrading of concrete structures with bonded steel or FRP (Fiber Reinforced Polymers) materials or by use of external tendons have now been used for some time. External prestressing may be defined as a prestress introduced by tendons located outside a section of a structural member, only connected to the member through deviators and end-anchorages. The main advantages using this technique are; higher utilization of small sectional areas, ease in inspection of the tendons and in their replacement and low friction losses. This type of prestressing can be applied to both new and existing structures that need to be strengthened due to several reasons such as: changes in use, deficiencies in design or construction phase and structural degradation. External prestressed cables of FRP materials have shown to be an alternative to steel cables. Good durability properties and a first-rate behaviour in creep and relaxation have given very good results so far. Bonding prestressed FRP laminates or sheets to a structures surface has proven to be efficient and gives also a better utilization of the strengthening material. The weak part for both external cables as well as bonded laminates, when using FRP materials, has shown to be anchorage. Often the anchorage has problem to handle the high stresses that would justify the use of FRP materials in prestressing. However this is changing with a number of research projects around the world focusing on the anchorage issue. This literature review gives a short description of external prestressing for concrete structures and steel structures. The report then focus on the different types of external prestressing, with steel tendons, FRP tendons and bonded FRP materials. A review of some examples of theory follows and then a view on some codes, ending the report with structures strengthened with external prestressing.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2005. , 81 p.
Technical report / Luleå University of Technology, ISSN 1402-1536 ; 2005:06
Research subject Structural Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-22954Local ID: 4fec32d0-2805-11dd-8187-000ea68e967bOAI: oai:DiVA.org:ltu-22954DiVA: diva2:996003
Godkänd; 2005; 20080522 (ysko)2016-09-292016-09-29Bibliographically approved